Mirrors (micro-mirrors), used to steer (direct), attenuate, or deflect an optical beam, are incorporated in many different devices including optical cross-connects. In U.S. Pat. No. 6,178,033, incorporated herein by this reference, a thin, deformable membrane with a deformable mirror thereon is supported above a substrate. When the deformable membrane is caused to deflect towards the substrate, the mirror deforms to steer (direct) an optical beam incident thereon.
Manufacturing such a deformable mirror, however, is troublesome and controlling such a deformable mirror and preventing it from curling is also problematic. In fact, the '033 patent discusses the need for a bossed frame used to stiffen the membrane area surrounding the mirror. Moreover, when the membrane and the deformable mirror are deflected closer to the substrate, the deflection angle of the membrane limits the angle of incidence and the angle of reflection of the deformable mirror. Also, once the membrane deforms to the extent that it contacts the substrate, no further adjustment of the deflection angle of the deformable mirror is possible, thus limiting the maximum deflection angle of the deformable mirror.